7828007778 has 16 divisors (see below), whose sum is σ = 17395572960. Its totient is φ = 2609335908.

The previous prime is 7828007741. The next prime is 7828007783. The reversal of 7828007778 is 8777008287.

It is a happy number.

It is a super-2 number, since 2×7828007778² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54), and also a Moran number because the ratio is a prime number: 144963107 = 7828007778 / (7 + 8 + 2 + 8 + 0 + 0 + 7 + 7 + 7 + 8).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 72481500 + ... + 72481607.

It is an arithmetic number, because the mean of its divisors is an integer number (1087223310).

Almost surely, 2^7828007778 is an apocalyptic number.

7828007778 is an abundant number, since it is smaller than the sum of its proper divisors (9567565182).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7828007778 is a wasteful number, since it uses less digits than its factorization.

7828007778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144963118 (or 144963112 counting only the distinct ones).

The product of its (nonzero) digits is 2458624, while the sum is 54.

The square root of 7828007778 is about 88476.0293977979. The cubic root of 7828007778 is about 1985.5633572427.

The spelling of 7828007778 in words is "seven billion, eight hundred twenty-eight million, seven thousand, seven hundred seventy-eight".